Mold assemblies comprising two side mold parts and a base mold part are commonly used in the formation of plastic containers such as, for example, biaxially-oriented PET (polyethylene terephthalate) beverage bottles. The side mold parts may comprise a unitary half-part, multiple half-parts or a unitary shell half insert.
In hot fill, applications, such as, for example, formation of juice containers that are subsequently filled with hot juices, it is important to maintain elevated temperature levels at the forming surface where the mold face contacts the plastic of the container to form a plastic container capable of withstanding hot filling temperatures of liquids subsequently filled in the container. This is typically accomplished by having heating passages contained in the mold through which hot fluid passes to keep the mold face at the elevated predetermined temperature. The problem with present molds is that heat dissipates away from the mold face to the outer walls of the mold requiring greater heat energy to maintain the elevated predetermined temperature. This heat dissipation also occurs in interchangeable mold shell inserts that are supported in direct contact with standardized mold carriers as the heat is dissipated by conduction directly from the shell insert and out through the mold carrier.